Rechargeable battery

Abstract

A rechargeable battery includes an electrode assembly having a first electrode, a separator, and a second electrode; a case accommodating the electrode assembly; an electrode terminal; a first current collecting plate connecting the first electrode to the electrode terminal; a vent plate; a second current collecting plate connecting the second electrode to a beading portion of the case at an inner side of the vent plate; and a gasket between the second collecting plate and the vent plate and between the second collecting plate. The second current collecting plate includes a base portion on the second electrode, a bottom welding portion extending in a radial direction from the base portion and welded to the second electrode, and a wing welding portion spaced apart from the bottom welding portion and connected to the base portion by an elastic portion and welded to the beading portion.

What is claimed is: 
     
         1 . A rechargeable battery comprising:
 an electrode assembly comprising a first electrode, a separator, and a second electrode in a jelly roll configuration;   a case accommodating the electrode assembly;   an electrode terminal in an insulating state at a first opening on one side of the case;   a first current collecting plate connecting the first electrode to the electrode terminal;   a vent plate sealing a second opening on an other side of the case;   a second current collecting plate connecting the second electrode to a beading portion of the case at an inner side of the vent plate; and   a gasket between the second collecting plate and the vent plate and between the second collecting plate and the case, the gasket forming a seal between a crimping portion and the beading portion of the case,   wherein the second current collecting plate comprises:
 a base portion on an uncoated portion of the second electrode, 
 a bottom welding portion extending in a radial direction from the base portion and welded to the uncoated portion of the second electrode, and 
 a wing welding portion spaced apart from the bottom welding portion and connected to the base portion by an elastic portion and welded to the beading portion of the case. 
   
     
     
         2 . The rechargeable battery as claimed in  claim 1 , wherein
 a plurality of the bottom welding portions and a plurality of the wing welding portions are alternately arranged in a circumferential direction of the base portion.   
     
     
         3 . The rechargeable battery as claimed in  claim 2 , further comprising
 a through-hole in a center of the base portion, and wherein   the bottom welding portion and the elastic portion are connected by a concave groove at the base portion.   
     
     
         4 . The rechargeable battery as claimed in  claim 3 , wherein:
 the bottom welding portion is coupled to the second electrode by a first welding line extending along a radial direction of the second current collecting plate, and   the wing welding portion is coupled to the beading portion of the case by a second welding line extending along a circumferential direction of the second current collecting plate.   
     
     
         5 . The rechargeable battery as claimed in  claim 4 , wherein
 the wing welding portion extends in the circumferential direction and is longer than a width of the elastic portion.   
     
     
         6 . The rechargeable battery as claimed in  claim 1 , wherein
 the elastic portion comprises:   a first elastic bending portion connected to the base portion, the first elastic bending portion being bent upwardly and is bent outwardly in a radial direction, and   a second elastic bending portion connected to the first elastic bending portion and the wing welding portion, the second elastic bending portion being bent upwardly and bent outwardly at an incline in the radial direction.   
     
     
         7 . The rechargeable battery as claimed in  claim 6 , wherein
 the gasket comprises an escape groove accommodating the wing welding portion.   
     
     
         8 . The rechargeable battery as claimed in  claim 7 , wherein:
 the beading portion comprises a flat portion on an upper side of an inwardly convex curved portion, and   the wing welding portion is welded to the flat portion.   
     
     
         9 . The rechargeable battery as claimed in  claim 8 , wherein
 the escape groove comprises a right angle at a side of the wing welding portion and an obtuse angle corresponding to the second elastic bending portion at an inner side in the radial direction.   
     
     
         10 . The rechargeable battery as claimed in  claim 1 , wherein
 an inner surface of the vent plate comprises a notch.